Paul Moushumi, Nuñez Alberto, Van Hekken Diane L, Renye John A
U.S. Department of Agriculture, Eastern Regional Research Center, Agricultural Research Service, 600 East Mermaid Lane, Wyndmoor, PA 19038 USA.
J Food Sci Technol. 2014 Nov;51(11):3432-8. doi: 10.1007/s13197-012-0868-8. Epub 2012 Oct 18.
Native microflora in raw milk cheeses, including the Mexican variety Queso Chihuahua, contribute to flavor development through degradation of milk proteins. The effects of proteolysis were studied in four different brands of Mexican Queso Chihuahua made from raw milk. All of the cheeses were analyzed for chemical and sensory characteristics. Sensory testing revealed that the fresh cheeses elicited flavors of young, basic cheeses, with slight bitter notes. Analysis by gel electrophoresis and reverse phase-high performance liquid chromatography (RP-HPLC) revealed that the Queseria Blumen (X) and Queseria Super Fino (Z) cheeses show little protein degradation over time while the Queseria America (W) and Queseria Lago Grande (Y) samples are degraded extensively when aged at 4 °C for 8 weeks. Analysis of the mixture of water-soluble cheese proteins by mass spectrometry revealed the presence of short, hydrophobic peptides in quantities correlating with bitterness. All cheese samples contained enterococcal strains known to produce enterocins. The W and Y cheese samples had the highest number of bacteria and exhibited greater protein degradation than that observed for the X and Z cheeses.
生乳奶酪中的天然微生物群落，包括墨西哥品种奇瓦瓦奶酪（Queso Chihuahua），通过降解乳蛋白促进风味的形成。对四种不同品牌的由生乳制成的墨西哥奇瓦瓦奶酪的蛋白水解作用进行了研究。对所有奶酪的化学和感官特性进行了分析。感官测试表明，新鲜奶酪呈现出年轻的基础奶酪风味，并带有轻微的苦味。通过凝胶电泳和反相高效液相色谱（RP-HPLC）分析发现，布卢门奶酪厂（X）和超级菲诺奶酪厂（Z）的奶酪随着时间推移蛋白质降解很少，而美国奶酪厂（W）和拉戈格兰德奶酪厂（Y）的样品在4℃下陈化8周时蛋白质被大量降解。通过质谱分析水溶性奶酪蛋白混合物发现，存在与苦味相关数量的短链疏水肽。所有奶酪样品都含有已知能产生肠菌素的肠球菌菌株。W和Y奶酪样品的细菌数量最多，并且比X和Z奶酪表现出更大程度的蛋白质降解。
